Epilepsy is a disorder that involves far more than the occurrence of seizures, and seizures can cause neuronal network disturbances that result in a wide range of cognitive and behavioral impairment. To date, most work in the epilepsy field has centered on the mechanism or prevention of the ictal events themselves. The focus of my laboratory has been on the impact of early life seizures on brain development and epileptogenesis. The present proposal extends our work to determine whether these mechanisms also induce alterations that could lead to cognitive dysfunction manifesting in early life, such as autism. There is clinical evidence that early life seizures may be one of many precedents for autism, and epilepsy is common in patients with autism, suggesting an interaction between the two processes. Our prior and recent work suggests that at least in the immature brain, where baseline synaptic plasticity is enhanced, seizures appear to directly activate specific plasticity-associated signaling pathways. We hypothesize that seizure induced ?dysplasticity? may occlude normal plasticity involved in cognition, and induce abnormal patterns of synapse development similar to those observed in autism and other forms of neurodevelopmental delay. Using electrophysiological techniques, we will first examine the time course of seizure-induced interruption of normal synaptic plasticity in the immature brain. We will then determine whether specific activity-dependent signaling abnormalities known to be associated with autism occur de novo following seizures in the immature brain. Next, we will identify seizure induced mechanisms for their activation and test whether post-seizure intervention attenuates the altered structure and function of neuronal networks. Finally, we will determine whether similar alterations in signaling, regulatory, and synaptic proteins also are observed in human tissue following seizures and in cases of autism associated with neonatal or infantile seizures.